The idea here is that a person can workout, and run, and bike like crazy, but if we don't find a way to make it fun or maybe even adventurous, we're much less likely to stay with it for a lifetime. So, if we can create that one big humongous reason to keep doing the work and staying fit and strong, we won't ever quit. Ever. And if we can make the "workout" fun or even adventurous, it makes it that much more rewarding!
The bonus is that after we run up that sand dune...